There are over 1000 species of freshwater mussels
in the world with over 300 species in North America.
New York is relatively mussel-rich with 50 species
primarily in the southern part of the state, but there
are only three known species of mussels on Fort
Drum.
The average freshwater mussel lives about 10 years,
but some species like the Eastern Pearl Shell found in
the western Adirondacks can live up to 100 years!
Historically, freshwater mussels were an important
food source for Native Americans. During the early
1900’s, freshwater mussels were exploited to make
buttons for clothing which led to significant
population declines. The invention of plastic buttons
has since replaced mussel shell buttons. Today, many
mussel species are endangered due to water
pollution, construction of dams, and competition with
invasive Zebra Mussels.
Like saltwater oysters, freshwater mussels can
produce pearls, although it is not common. Pearls
are actually produced as a defense mechanism.
When a foreign object gets inside the shell and
becomes an irritation, the natural defense of the
mussel (or oyster) is to cover the foreign object with
a nacre substance; the same material used in
forming the inside of a mussel shell. The nacre
substance around the irritant forms the pearl.
Photo Credits: All photos are used with permission from: Jim Mason & M.C. Barnhart with Unio Gallery at Missouri State University (www.unionid.missouristate.edu) and Illinois State Museum (www.museum.state.il.us).
Cover Photos: (top) Black Sandshell Mussel feeding; (middle) pile of Pearly Mussels; and (bottom) Ouachita Kidneyshell Mussel.
Per New York State regulations:
It is illegal to collect or harvest living freshwater
mussels in New York without a special scientific
collection permit issued by the NYS Department of
Environmental Conservation
(Dreissena polymorpha)
INTRODUCED INVADER! Zebra Mussels were first introduced to the United
States in 1988 near Detroit, Michigan. Since then,
they have spread and can be found from coast to
coast. While not all lakes and rivers are infested
with zebra mussels, once infested, zebra mussels
can drastically change the complexion of a water
body. Like all mussels, Zebra Mussels are filter
feeders. However, Zebra Mussels are known for
their ability to filter large quantities of water and
removing zooplankton from the water column
which are an essential food for young fish.
In some cases zebra mussels can produce up to one
million eggs per year, allowing them to take over
lakes and rivers very quickly. It is estimated that
zebra mussels cause over 100 million dollars in
damage a year. To prevent the spread of zebra
mussels, please check your boat for mussels as you
move from one body of water to another.
Generally about an inch long, they can be identified
by their triangle shape and the zebra pattern on their
shells.
Anatomy of a Freshwater Mussel
Natural Resources Branch
Environmental Division
Directorate of Public Works
Fort Drum, NY
315-772-6283/ 772-9636
www.fortdrum.isportsman.net
2018
1a. Mussel shell triangle-shaped with alternating light
and dark banding (Fig. 1)……………………...Zebra Mussel
1b. Not as above…………………………………………………….2
The Eastern Elliptio is one of the most abundant
mussels in North America and is the most
common mussel found on Fort Drum. The Eastern
Elliptio can live up to 15 years and can be found in
both fast and slow moving water bodies, and in
almost any substrate type, allowing them to thrive
in lakes, rivers, ponds and streams. This mussel is
a vital food source for muskrats and otters.
The Eastern Elliptio has a history of being very
resilient and widespread because of its ability to
withstand conditions other mussels can not, such
as pollution, dam building and dredging. They
have also withstood heavy harvesting in the late
1800’s and early 1900’s, when their shells were
used to make buttons.
This species is easily identified by their shape and
color. The outside of their shell is often a dark
brown, while the inside or nacre has a purple hue.
The picture above depicts a typical Eastern Elliptio
mussel.
(Elliptio complanata)
The Eastern Floater is another widespread and
common species. They can be found in a variety of
habitats, but are most commonly found in calm
protected waters with sandy or muddy bottoms.
The Eastern Floater is found in numerous locations
around Fort Drum, but is most abundant in Indian
Pond. The Eastern Floater often exceed 10 inches
in length and is the largest mussel found on
Fort Drum.
(Pyganodon cataracta)
Figure 3. Eastern Floater
Figure 1. Zebra Mussel
Figure 4. Eastern Elliptio
(Lampsilis radiata)
The Eastern Lampmussel is the rarest mussel on Fort
Drum. They tend to reside in moderate- to fast-flowing
streams and rivers, but can be found in larger bodies of
water as well. The Eastern Lampmussel prefers sandy
or gravel substrate, but will colonize a variety of other
substrates if sandy sediments aren’t available. This
mussel has thus far only been found in two locations
on Fort Drum; Indian Lake and the Indian River.
Though not legally protected in New York, the Eastern
Lampmussel is classified as endangered or critically
imperiled in many states such as Pennsylvania, North
Carolina, and Delaware.
The Eastern Lampmussel can
be identified by its circular
shell, which is often yellow and
green, but older specimens
tend to turn brown. Another
key identifying feature are the
distinct dark lines which run
vertically down their shells.
Eastern Lampmussels can live
up to 30 years making them the longest lived species
of mussel on Fort Drum.
Fig. 2 Eastern Lampmussel
The Eastern Floater is found along the east coast of
the US and is secure throughout most of its range;
though it is less abundant in southern states. These
mussels can be easily identified by their brittle green
and yellow shells. Because their shells are so brittle,
predators can easily crack them open making them
a preferred food source for many wildlife species. 2a. Mussel shell circular in shape (Fig. 2)………………...
…………………………………………………Eastern Lampmussel
2b. Mussel shell elongate in shape (Fig. 3)……………….2
2a. Lateral Teeth Present (Fig. 4)………..Eastern Elliptio
2b. Lateral teeth absent (Fig. 5)………….Eastern Floater
Lateral Teeth Absent
Fig. 5 Eastern Floater
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